Use of TAI...

[jcomm 6,004]

Two questions...

 

1) At cruise I have selected TAI on the left engine. AT was engaged. All engine parameters remain equal on both engines, with TAI indicated on the left engine as supposed.

 

Shouldn't I see a drop in power / N1 on that engine?

 

2) At iddle, A/T off, I engage TAI on left engine. Both engines seem to adjust symmetricaly ( increase in N1). Shouldn't this occur only on the left engine?

 

3) Is the loss of power when TAI is engaged simulated?  If yes, is it always symmetrical, even if only one of the engines get's TAI switched ON?

[machine2035 176]

Two questions...

 

1) At cruise I have selected TAI on the left engine. AT was engaged. All engine parameters remain equal on both engines, with TAI indicated on the left engine as supposed.

 

Shouldn't I see a drop in power / N1 on that engine?

 

2) At iddle, A/T off, I engage TAI on left engine. Both engines seem to adjust symmetricaly ( increase in N1). Shouldn't this occur only on the left engine?

 

3) Is the loss of power when TAI is engaged simulated?  If yes, is it always symmetrical, even if only one of the engines get's TAI switched ON?

N1 drop is probably symmetrical due to the EEC's. I assume the EEC's change the N1 (due to the increase demand of bleed air [DEU detects anti-ice operation]) on both engines to stop the chance of asymetric thrust.

 

Anyway it is not normal to have one engine AI on, but not the other.

 

Also, in cruise, if your thrust is below what the EEC's have computed to be the Max N1 for when the AI systems are on, I don't think the N1 would reduce further. If current N1 < Max N1 computed by EEC's, N1 setting should stay the same.

[jcomm 6,004]

Thx James!

[Vagabondo 23]

Two questions...

 

1) At cruise I have selected TAI on the left engine. AT was engaged. All engine parameters remain equal on both engines, with TAI indicated on the left engine as supposed.

 

Shouldn't I see a drop in power / N1 on that engine?

 

2) At iddle, A/T off, I engage TAI on left engine. Both engines seem to adjust symmetricaly ( increase in N1). Shouldn't this occur only on the left engine?

 

3) Is the loss of power when TAI is engaged simulated?  If yes, is it always symmetrical, even if only one of the engines get's TAI switched ON?

 

1) This is a simplistic way of viewing engine thrust, but generally, all other things being equal (OAT, pressure, TAS)) N1 = thrust. To maintain a speed in cruise a specific level of thrust is required hence N1 not changing much. If TAI is selected on, N1 should be more or less the same. You should see a slight increase in fuel flow with engine TAI on - this however is not reflected or explained in the FCOM1 Performance Inflight tables, I need more info to clarify this.

 

2) The EEC engine idle is changed to approach idle for both engines, when either engine TAI is selected on in flight.

 

3) Power (thrust) loss would only really be evident near max rated thrust with significant bleed demand (such as packs and/or wing anti-ice). Engine TAI on its own does not affect take off or go-around performance, I presume because other factors such as fuel flow and engine compression are not, with such a small bleed demand, limiting or limited factors.

[jcomm 6,004]

Ok,

 

excellent answers!

 

I remember it had some noticeable impact on some of the models in Aerowinx PS1 ( b744) and that's why I asked!

[machine2035 176]

Ok,

 

excellent answers!

 

I remember it had some noticeable impact on some of the models in Aerowinx PS1 ( b744) and that's why I asked!

Another PS1 user....Cool.

 

Can't wait for PSX, eh ^_^ ^_^

[Vagabondo 23]

You'll enjoy this then

 

http://aerowinx.com/forum/topic.php?id=1382

[jcomm 6,004]

Yes! Been following it ever since I bought PS1 in 1997 :-)

 

Used it together with fs9, fsx and even flight gear for the World views, thanks to some genial creations by some elements of the Aerowinx users community.

 

Looking fwd for PSX of course :-)